12,030 research outputs found
EMPLOYMENT, GENDER, EDUCATION AND OTHER RELEVANT VARIABLES: THE FINANCIAL CRISIS IMPACT IN SPAIN
Abstract The present paper aims to ascertain whether gender differences continue to exist in Spain’s working population. It sets out to obtain empirical evidence of the employment profile according to gender, quantify the extent to which self-employment or salaried employment is associated with certain characteristics (age, education, marital status and economic sector) and to analyse the evolution undergone during the recent economic crisis (2005-2009). In the study multivariate analysis statistical techniques will be applied to micro-data from the Working Population Survey compiled by Spain’s National Statistics Office (INE). Results shows that significant gender differences in employment status are seen when this is disaggregated and that the economic crisis has had a negative impact especially in certain groups.
Numerical study of relaxation in electron glasses
We perform a numerical simulation of energy relaxation in three-dimensional
electron glasses in the strongly localized regime at finite temperatures. We
consider systems with no interactions, with long-range Coulomb interactions and
with short-range interactions, obtaining a power law relaxation with an
exponent of 0.15, which is independent of the parameters of the problem and of
the type of interaction. At very long times, we always find an exponential
regime whose characteristic time strongly depends on temperature, system size,
interaction type and localization radius. We extrapolate the longest relaxation
time to macroscopic sizes and, for interacting samples, obtain values much
larger than the measuring time. We finally study the number of electrons
participating in the relaxation processes of very low energy configurations.Comment: 6 eps figures. To be published in Phys. Rev.
Hyperonic crystallization in hadronic matter
Published in Hadrons, Nuclei and Applications, World Scientific, Singapore,
Proc.of the Conference Bologna2000. Structure of the Nucleus at the Dawn of the
Century, G. Bonsignori, M. Bruno, A. Ventura, D. Vretenar Editors, pag. 319.Comment: 4 pages, 2figure
Discovery of a wide companion near the deuterium burning mass limit in the Upper Scorpius association
We present the discovery of a companion near the deuterium burning mass limit
located at a very wide distance, at an angular separation of 4.6+/-0.1 arcsec
(projected distance of ~ 670 AU) from UScoCTIO108, a brown dwarf of the very
young Upper Scorpius association. Optical and near-infrared photometry and
spectroscopy confirm the cool nature of both objects, with spectral types of M7
and M9.5, respectively, and that they are bona fide members of the association,
showing low gravity and features of youth. Their masses, estimated from the
comparison of their bolometric luminosities and theoretical models for the age
range of the association, are 60+/-20 and 14^{+2}_{-8} MJup, respectively. The
existence of this object around a brown dwarf at this wide orbit suggests that
the companion is unlikely to have formed in a disk based on current planet
formation models. Because this system is rather weakly bound, they did not
probably form through dynamical ejection of stellar embryos.Comment: 10 pages, including 4 figures and 2 table
High Gain Amplifier with Enhanced Cascoded Compensation
A two-stage CMOS operational amplifier with both, gain-boosting and indirect current feedback frequency compensation performed by means of regulated cascode amplifiers, is presented. By using quasi-floating-gate transistors (QFGT) the supply requirements, the number of capacitors and the size of the compensation capacitors respect to other Miller schemes are reduced. A prototype was fabricated using a 0.5 μm technology, resulting, for a load of 45 pF and supply voltage of 1.65 V, in open-loop-gain of 129 dB, 23 MHz of gain-bandwidth product, 60o phase margin, 675 μW power consumption and 1% settling time of 28 ns
Ultra Low-Power Analog Median Filters
The design and implementation of three analog median filter topologies, whose transistors operate in the deep weak-inversion region, is described. The first topology is a differential pairs array, in which drain currents are driven into two nodes in a differential fashion, while the second topology is based on a wide range OTA, which is used to maximize the dynamic range. Finally, the third topology uses three range-extended OTAs. The proposed weak-inversion filters were designed and fabricated in ON Semiconductor 0.5 micrometer technology through MOSIS. Experimental results of three-input fabricated prototypes for all three topologies are show, where power consumptions of 90nW in the first case, and 270nW in the other two cases can be noticed. A dual power supply +/-1.5 Volts were used
An empirical calibration of sulphur abundance in ionised gaseous nebulae
We have derived an empirical calibration of the abundance of S/H as a
function of the S23 parameter, defined using the bright sulphur lines of [SII]
and SIII]. Contrary to what is the case for the widely used O parameter,
the calibration remains single valued up to the abundance values observed in
the disk HII regions. The calibration is based on a large sample of nebulae for
which direct determinations of electron temperatures exist and the sulphur
chemical abundances can be directly derived. ICFs, as derived from the [SIV]
10.52 emission line (ISO observations), are shown to be well reproduced
by Barker's formula for a value of alpha = 2.5. At any rate, only about 30% of
the objects in the sample require ICFs larger than 1.2. The use of the proposed
calibration opens the possibility of performing abundance analysis with red to
IR spectroscopic data using S/H as a metallicity tracer.Comment: 9 pages, 5 figures. Accepted for publication by Astronomy &
Astrophysic
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